Many applications exist in which it is desired to precisely and rapidly move an element. For example, it may be desired to move the element from one location to another in the shortest period of time and to locate the element at the end of such move with a high degree of precision. Such applications may include machine tools in which it is desired to move a cutting tool, such as a drill, to a precise location for drilling a hole. Numerous other applications, such as cut-to-length apparatus and press feeders, exist.
Various types of drives have been devised to provide such movement and location. In the past, however, problems have arisen with the drives. Among these problems are the instabilities attendant the various control loops found in such drives including the inability to adjust one physical or electronic aspect, such as acceleration, maximum speed, or amplification, without causing a deterioration in the performance of the drive or without requiring compensating adjustment in all the control aspects.
Prior art devices have failed to use the full horsepower capabilities of the drive motor. This has reduced operating speeds and times or required oversizing of the motor to provide adequate operating characteristics.